Applicants claim priority under 35 U.S.C. xc2xa7119 of GERMAN Application No. 199 28 448.2 filed on 23 JUN. 1999. Applicants also claim priority under 35 U.S.C. xc2xa7371 of PCT/DE00/01623 filed on 19 MAY 2000. The international application under PCT article 21(2) was not published in English.
The invention concerns a ring filter made of star-shaped folded filtering material.
A ring filter of this type is known from EP 0 498 757 Al.
The invention concerns itself with the problem of designing the closure on the front side in the ring filter according to the preamble, particularly using a foamed, elastic plastic closure material, so it is durable, as well as allowing an economical production of the closure region of this type of filter through an appropriate design of the closure region. In addition, a constructive design is to be provided in the closure region on the front side which ensures a secure and tight attachment of the closure material to the folded filtering material.
This problem is solved by the implementation of a ring filter described below.
Advisable embodiments are the object of the sub-claims and will be described in more detail with reference to an illustrated exemplary embodiment.
The following particular advantages arise through the solution according to the invention.
Particularly in ring filters having large dimensions, such as in ring filters which are, for example, intended as air filters for commercial vehicles, and in which the closure material consists of a foamed plastic material having elastic properties, not only is expensive plastic material saved by the plate-shaped insert, but the closed ring filter floor can be reliably protected from oscillations of the floor, which cause unpleasant noises, by the selection of a stiff material for the plate-shaped insert. These types of floor oscillations can, as a rule, not be avoided with a continuous floor made of foamed, elastic plastic material.
The connection of the plate-shaped insert into the closure on the front side of the ring filter element allows an economic production of the filter, because the plate-shaped insert can be inserted together with the ring filter element and the tubular frame present therein into the mold, in which the closure on the front side is molded onto the filtering material, including the tubular frame supporting the material.
If a connection of the plate-shaped insert to the tubular frame is selected in which the plate-shaped insert is fixed axially inside the tubular frame, a particularly durable attachment of the plate-shaped insert in the molded-on closure material is ensured. The connection region is then not subjected to floor oscillations during operation of the filter.
A precise production of the ring filter in regard to its length is allowed by axial fixing of the plate-shaped insert on the tubular frame of the ring filter. More detail is provided on this matter in the description of the exemplary embodiment.